1. Field of the Invention
This invention relates to an improved air filter assembly, and more particularly, to an air filter assembly that is efficiently installed and replaced, providing a more effective method for removing contaminants from air.
2. Description of the Prior Art
Filter assemblies are conventionally used within automobile air filtration systems. A typical automotive air filter assembly includes a conical filter element, as disclosed in U.S. Design Pat. No. 428,128.
Another example of a conical filter element used in an automotive air cleaner unit is disclosed in U.S. Pat. No. 5,685,887. The filter element includes a corrugated filter surface having a plurality of pleats forming rows of hills and valleys slantwise on a corrugated sectional surface. The pleats are angled tangentially relative to a longitudinal axis of the filter element.
Filter elements are typically used within tubular housings or shells. U.S. Pat. No. 6,258,144 discloses a filter element for an engine that includes two conical netted filter members mounted within a tubular member.
U.S. Patent Application Publication No. 2002/0040569 discloses a filter assembly for the intake air of an internal combustion engine that includes a conical filter element mounted within a two-piece shell. The two shell pieces are joined by a groove and collar connection. The shell has two openings, an inlet and an outlet. The inlet is positioned offset from a central axis of the housing shell and directs air to one side of the filter element. The outlet is positioned to receive filtered air from the filter element along a central axis of the shell.
U.S. Pat. No. 5,902,365 discloses for an internal combustion engine a filter assembly having a tubular housing and a frusto-conical filter element. The frusto-conical filter element includes a nose plug, a filter, and a base ring. The filter includes a sheet of filter media pleated and folded to form a frusto-conical shape. The pleats extend along an elongated surface of the filter element from the nose plug to the base ring. The filter element is positioned within a housing by inserting a circumferential lip on the base ring into a circumferential recess of the housing.
U.K. Patent Application GB 2 064 359 discloses a two component filter unit for an internal combustion engine air intake. The filter unit includes a cylindrical body member and a frusto-conical filter element. A top portion of the frusto-conical filter element is dimensioned such that the cross-sectional area of the airflow passage between its minimum diameter and the inner-cylindrical surface of the body is equal to the cross-sectional area defined by a tubular member. The cross-sectional area of the airflow passage between its minimum diameter and the inner-cylindrical surface of the body is also equal to the cross-sectional area of the flow passage designed by the baffle.
U.S. Pat. No. 5,972,059 discloses a filter assembly for use in a dust collecting system. The filter assembly includes a cylindrical housing and a pleated conical filter element. The filter element is inverted to receive contaminated air through the base. The air passes through the filter and flows by the apex to an outlet in the housing. A brace is attached to the apex of the conical filter element to hold the filter element in place. The brace includes a cap having a smooth aerodynamic shape.
Other air filter elements having smooth aerodynamic conical shapes are known in the art. U.S. Pat. No. 4,157,902 discloses an air cleaner designed for insertion in the air intake conduits of over-the-road vehicles. The air cleaner includes a tubular housing and a conical member. The member includes a section covered by pleated paper to form a filter element. The member includes a conical cap section having a smooth aerodynamic shape. The member is attached to the housing with a plurality of bolts.
U.S. Pat. No. 5,549,722 discloses a filter assembly having a filter housing, a frustoconical filter element, and a base. The frustoconical filter element includes a cone diffuser having a smooth aerodynamic shape. The base includes a flange. The filter housing is clamped to the flange on the base portion.
U.S. Pat. No. 6,319,298 discloses a two component filter system having a non-metallic housing that functions as a heat shield and an air filter element. The air filter element includes a dome shaped cap supported by a truncated cone shaped filter element. The heat shield is mounted on a clamp and surrounds the air filter element. The heat shield is made of a low heat conducting material, such as high impact plastic.
The geometry of the housing and the filter element are often important factors in the design of an air filter assembly. Accordingly, there is need for an air filter assembly that distributes the flow of air evenly across the surface of the filter element. A housing designed to position a filter cap to accelerate the flow of contaminated air through the filter assembly is also desirable.
The attachment of the housing in surrounding relation to the filter element is another important factor in the design of a filter assembly. The housing should be positioned relative to the filter element to optimize the flow of air through the filter element to improve filter efficiency. The housing should be connected to the filter element to facilitate ease in installation and replacement of the filter in the housing. Accordingly, there is a need for an air filter assembly having a housing efficiently connected to the filter element for promoting uniform flow of air into and surrounding the filter element.
In accordance with the present invention there is provided an improved air filter that includes a filter element formed of an air permeable material. The filter element has a conical-shaped body portion with an open upper end portion and an open lower end portion. The open upper end portion has a smaller diameter than the diameter of the open lower end portion. A cap is positioned in the filter element open upper end portion to close the open upper end portion. The cap has a conical configuration with a plurality of turbine blades extending in spaced relation on the surface of the cap to form channels between the turbine blades. The channels accelerate the flow of contaminated air between the turbine blades into the filter element. A cylindrical base has an open enlarged end portion and an open reduced end portion coaxially aligned with and extending from the open enlarged end portion. The base open enlarged end portion extends into said filter element open lower end portion to support the filter element on the base. A clamping mechanism circumscribes the filter element lower open end portion in surrounding relation with the base open enlarged end portion for connecting the filter element to the base to form an outlet for directing the accelerated flow of air free of contaminants out of the filter element.
Further in accordance with the present invention, there is provided an air filter assembly that includes a filter element formed of an air permeable material. The filter element has a conical-shaped body portion with an upper end portion closed by a cap and an open lower end portion. A resilient collar extends axially from the filter element open lower end portion. A cylindrical base member has an inlet end portion and an outlet end portion with a radial portion positioned intermediate the inlet and outlet end portions. The base member inlet end portion extends into sealing engagement with said collar to axially position the filter element on the base member. A housing surrounds the filter element and has a cylindrical open upper end portion and an elongated frusto-conical body portion. The housing body portion has a lower end positioned on the base member radial portion to axially position the housing on the base member and thereby coaxially align the housing and the filter element to assure uniform spacing between the housing and the filter element the length of the filter element in the housing for the flow of air into the housing and through the filter element.
Further in accordance with the present invention, there is provided a method for assembling an air filter that includes the step of supporting a lower end portion of a conical filter element on a cylindrical base. The filter element is clamped to the base to maintain the filter element in axial alignment with the base. A conical housing having opposite open end portions is positioned in surrounding relation with the filter element. A large diameter end portion of the housing is positioned on the base in surrounding relation with the filter element secured to the base. The housing is secured to the base so that the housing is axially aligned with the base to coaxially position the housing and the filter element to maintain uniform spacing between the housing and the filter element for the flow of air into the housing and through the filter.
Accordingly, a principal object of the present invention is to provide an air filter assembly including a base that releasably attaches to a tubular housing for ease of installation and replacement of an air filter element.
Another object of the present invention is to provide an air filter assembly having a cap with a plurality of turbine blades that distribute contaminated air evenly across the filter surface by creating a swirling effect within a housing.
A further object of the present invention is to provide a tubular housing that accelerates the flow of contaminated air within an air filter assembly providing a more efficient filtering system.
A further object of the present invention is to provide a tubular housing and base that are positioned relative to one another to accelerate the flow of contaminated air while achieving an even flow of contaminated air across the surface of the filter element.
A further object of the present invention is to provide an air filter element that includes a resilient collar that is tightly clamped to a rigid base to dampen the vibration of the filter element as air flows through the filter element.
These and other objects of the present invention will be more completely described and disclosed in the following specification, accompanying drawings, and appended claims.